Braking and lock mechanisms for many gerotor motors and pumps are typically provided to prevent rotation of hydraulic torque transmissions systems when not in use.
In some vehicle applications for low-speed, high-torque gerotor motors, it is desirable for the motor to have some sort of parking brake or parking lock, the term “lock” being preferred because it is intended that the parking lock be engaged only after the vehicle is stopped. In other words, such parking lock devices are not intended to be dynamic brakes, which would be engaged while the vehicle is moving, to bring the vehicle to a stop.
Many brake and lock mechanisms for motors in general, and especially for hydraulic gerotor set motors, use a piston that is actuated by the hydraulic inlet pressure to disengage the brake/lock mechanism. However, the supply pressure for these pistons may not have a constant supply of pressurized fluid to ensure that the mechanism remains desirably disengaged.